Air traffic controllers must carefully monitor the flow of air traffic to guarantee its safety and efficiency. One of their goals can be optimizing the landing of aircraft by minimizing the time between landings, which increases runway throughput. Time between landings is controlled by the distance between aircraft. Thus, controllers can minimize the time between landings by minimizing the distance between aircraft while at the same time maintaining minimum separation distances required for safety. Without appropriate tools, air traffic controllers estimate or manually calculate aircraft separation, which can consume extra time, be imprecise, and be less efficient.
Tools are available to assist controllers in managing spacing for incoming aircraft that are on final approach. Spacing information may be displayed on an air traffic control display for aircraft that are on the final approach course. The displayed information can help air traffic controllers guide aircraft on the final approach course to minimize excess separation between aircraft while maintaining safe separation.
For many airports, the final approach course may be about 20 nautical miles long with a central axis defined by an extension of the runway centerline. An electronic beam, called the Instrument Landing System localizer, provides lateral guidance to aircraft along the final approach course. The spacing of incoming aircraft that are not yet established on the localizer is managed by controllers to minimize the later spacing on the final approach course. However, conventional systems cannot display the separation information for these aircraft because the aircraft are not lined up in an easy to determine sequence. While existing arrival management systems can support controllers by assigning arrival time for each aircraft based on the runway capacity, controllers must mentally convert this information into aircraft separation.